1. Field of the Invention
The present invention relates to a semiconductor multichip module, and more particularly to an improved semiconductor multichip module that can be fabricated by simplified assembly steps and that can enhance productivity.
2. Description of the Prior Art
U.S. Pat. No. 5,250,843 discloses a general repairable multichip module. To fabricate that module, an encapsulant, metallic wires, an insulation layer and the like are formed on a semiconductor chip using methods such as etching, and ultraviolet setting. The metallic wires are removed using solvent in order to replace defective chips. That is, using a chemical or physical method, the defective chips are removed and replaced by normal chips to thereby complete the multichip module. The resulting conventional multichip module will now be described.
With reference to FIG. 1 showing a cross-sectional view of a repairable multichip module according to the conventional art, the multichip module includes: a semiconductor substrate 1; an adhesive 2 coated on the substrate 1; a plurality of semiconductor chips 3 attached on the adhesive 2 and spaced from each other by a certain distance; an encapsulant 4 patterned to expose a plurality of pads (not shown) formed on each of the chips 3 therethrough and to partially seal the plurality of chips 3; metallic wires 5 formed along the surface of the patterned encapsulant 4 for electrical connection; and an insulation layer 6 formed along the metallic wires 5 for electrical insulation. Therein, reference numeral 7 denotes a patterned conductor.
The steps for fabricating the thusly constituted repairable multichip module according to the conventional art will now be described.
The adhesive 2 having a predetermined thickness is formed on the substrate 1. The plurality of chips 3 are respectively attached on predetermined locations of the adhesive 2. The encapsulant 4 is molded surrounding the plurality of chips 3. The encapsulant 4 is partially etched to expose the plurality of chip pads (not shown) therethrough. A metallization process is carried out to form the metallic wires 5 along the surface of the encapsulant 4, and an insulation process is carried out to form the insulation layer 6 on the surface of the encapsulant 4. The patterned conductor 7 is formed along the insulation layer 6 using an etching method, thereby completing its fabrication method.
As described, the repairable multichip module is fabricated using a plurality of complicated steps such as a metallization step, an insulation step, an etching step and the like, making it difficult to improve productivity and accomplish cost reduction.
Further, the removal or replacement of defective chips with normal chips has required complicated steps. For instance, defective chips detected after assembly should be removed by employing a chemical or physical method such as solvent-applied metallic wire removal and selective ultraviolet scanning.